An automatic microscope is used in imaging hematocytes in a sample in which blood is smeared on a slide glass, in imaging sediments in a sample in which sediments in urine are collected and spread over the plate, and in imaging samples in which a cross section of the cell is dyed. The automatic microscope includes a stage that freely moves at least in the XY direction and a microscope for magnifying the specimen of blood cells and the like applied to the slide glass arranged on the stage, and has a detecting function of detecting the object to be observed by moving the stage, and an auto focusing function of adjusting the relative position of the lens of the microscope and the stage to focus the focus of the lens on the specimen on the slide glass.
Such automatic microscope is generally used as an automatic analyzing apparatus equipped with a means for imaging an image of the specimen magnified by the microscope, and an image processing section for processing the imaged image to obtain the desired analysis information (e.g., number of hematocytes for each category) (see e.g., Japanese Patent Application Laid-Open (JP-A) No. 7-20124).
Japanese Laid-Open Patent Publication No. 7-20124 discloses a blood cell analyzing apparatus for categorizing the hematocytes of the blood cells and counting the numbers thereof, the apparatus including a microscope for magnifying the blood cells smeared on the slide glass and a color television camera for imaging the microscope image. The slide glass applied with the blood is mounted on the stage of the microscope. The stage is moved in the XY direction by a stage driving circuit to adjust the position of the slide glass on the stage, and the lens system is moved in the up and down direction (Z-axis direction) by a focus driving circuit to adjust the focusing position by auto focusing. The image from the microscope is imaged by means of the color television camera, and the image of the blood cell is displayed on an RGB monitor.
In the blood cell analyzing apparatus, the position of the slide glass is adjusted by moving the stage, but residual vibration is produced at the stage due to law of inertia when the stage is stopped after position adjustment. If auto focusing is performed before the residual vibration is converged, the focus of the lens cannot be reliably focused on the specimen on the slide glass. Thus, a predetermined time has to be waited until the residual vibration converges, and auto focusing must be performed after the residual vibration is converged. Since the analysis of the blood cell includes imaging of a predetermined number of (e.g., 100) white blood cell, the residual vibration must be waited until converged for each imaging to analyze one specimen, whereby the processing speed of the apparatus becomes low.